#include<iostream>
using namespace std;
long long brcifri(long long k){
    if(k<10){
        return 1;
    }else{
        return 1+brcifri(k/10);
    }
}
long long reverse(long long x){
    long long y=0,broqch;
    for(broqch=0;x>0;broqch++){
        y=y*10+x%10;
        x=x/10;
    }
    return y;
}
int main(){
    long long dolnagranica,gornagranica,chislitel,znamenatel,i,brneobiknoveni=0;
    cin>>dolnagranica>>gornagranica>>chislitel>>znamenatel;
    for(i=dolnagranica;i<=gornagranica;i++){
        if(i%chislitel==0&&reverse(i)%znamenatel==0&&i/chislitel==reverse(i)/znamenatel){
            brneobiknoveni++;
        }
    }
    cout<<brneobiknoveni<<'\n';
    return 0;
}